Fly screen over radiator or not?

More info would be handy.....what sort of vehicle? Why does it have 4 radiators (or are you including oil cooler, intercooler, air conditioner's condenser etc).

A rule of thumb is that turbo'd vehicles need free-flowing air (at least the Patrol's do), and Nissan recommend NOT to use a insect screen on it's turbo trucks.

If it's going to get clogged with insects, then the less airflow with a screen would be preferable to no airflow with a blanket of locusts. Farmers use shade cloth when the locusts are bad.

I have used a flyscreen type filter on a couple of Hilux used as agricultural spray
rigs & works fine but required daily maintenance, sometimes hourly in bad seed conditions but I would be reluctant to recomend same in your case. I found that
the majority of rubbish etc actually got in not through the front grille but through the vents & gaps under & through the Bull bar. I fitted a shadecloth screen under
neath & works a treat, wears out occassionally though. I imagine there is an
aftermarket screen made for your grille you could try. Just keep one eye on the
temp needle.
Compressed air is good, from the inside, but sometimes access can be difficult,
avoid direct contact with cooling fins & I have seen fins flattened by too much
pressure & the wrong angle of application. Many local cockies use shadecloth in the
centre of the bullbar to deflect grasshoppers, seems to work too.....oldbaz

All our off-road vehicles have doubled-over fly screen (two layers) in front of the radiator, mainly for grass seeds.

The local Toyota dealer actually does this standard (that's to say, when I picked up my Hilus he'd done it without being asked, and said they do it for virtually all the 4wds they sell) because most people round here do it anyway.

Go for it.

Flyscreen is the go for highway and local trips, if going into desert country I take a piece of shadecloth to put over the bullbar/outside as well.
Only use the nylon/fibreglass flywire as the aluminium and metal ones rub and when mixed with red dirt and water corrode very quickly.
I just get the overall width required, 1200/1500 etc and rock down to the hardware and buy enough for about three screens, cut them to size and shape and keep a spare in the truck in case you need a replacement while on a trip.
I tie mine in with cable ties.
Much easier sweeping the crap off the outside with abrush than picking it out of the cores, never had a prob with cooling on a variety of vehicles either.

Thanks for all that, I will use some nylon screen and see how it goes.

F4phantom,
I have had a fly screen mounted in front of my radiator for years with no noticeable rise in engine temp. It slides upward and out for cleaning. On my rig pic you can see it mouted behind the spotties. Made out of ally frame with security grill backing.
Seems to keep the rubbish out.
Cheers,
Bros.

As mentioned fly screen is your best option. There are premade screens available from auto shops, but they charge you for the privelage :)

Beaaware that some shade cloths available also have a wind rating, i.e. they will cut air flow by x%.

With the mesh screen (soft material), measure up, get some 2" black clothh tape, & sew a perimeter all around. At strategic points put some brass eyelets in, add string/rope or similar to tie to the bull bar or parts of the underside of front of vehicle. Take care to avoid any contact, rope or mesh, with any visible painted parts as dirt/mud is picked up and abrades the paint.

I wouldn't leave town without it. You can get a plastic flyscreen (not metal or covered metal) from Bunnings. Get the biggest width and plenty of it. Use cable ties on triple folded seams. Worth spending the time to do a neat job for efficiency and aesthetics. I put mine behind the grille so you wouldn't even know it's there.

Having dealt with both locusts and spinifex you must do a thorough job. Keep it away from the radiator and make sure you get the whole way underneath too.

With grass seeds they will still get in no matter what you do but this slows them down.